Hewland NMT, Servicing Instructions

Page: 11 / 40

PAGE 11
© Copyright Hewland Engineering Limited
GEARBOX - ASSEMBLY
a/
It is assumed that all bearings, oil seals, studs, oil jets, and dowels are already fitted into casing. (see page 5).
b/
Assemble the oil pump components (if required). Heat the maincase, and drop the pump into position. Secure with screws , and add the drive
gear and circlip.
c/
Place the reverse idler gear (104), bearing (106), and thrust washers (107) in position in the bearing carrier, and slide the spigot (105) into
position. Secure with screw (12).
d/
Assemble the selector rack (75), washers (76), spring (77), and circlip (78), and slide into the maincase. Secure with the selector rack stop
(80). Note: Check the gear linkage return spring length regularly (item 77). This spring has a finite life and will weaken with use. A new
spring has a free height of 1.450”. It is also adviseable never to re-use the circlip (78).
e/
Assemble the drum (8), bearing (28), pin (10), retaining plate (11), barrel driver (13), and shifter spindle (7). Assemble the drum shifter (6),
guide plate (9), pawls (64), springs (63), and plungers (62), and slide into engagement with the drum assembly. Push the complete assembly
into it's location in the maincase, ensuring correct location with the selector rack teeth.
f/
Assemble the selector input shaft (70), bearing (68), seal (71), spacer (72), quadrant gear (73) and circlip (112) into their housing (66). Slide
the whole assembly into the maincase, ensuring correct engagement with the selector rack (75).
g/
Build the selector barrel parts into the bearing carrier as described in the section 'Sequential Barrel Setting'.
h/
Fit the pinion shaft as described previously.
i/
Hold the reverse selector fork (31), with reverse pinion gear (121), in position in the bearing carrier (2). Slide the reverse selector shaft (110)
into place and secure with screw (122).